Ink jet printing systems are known in which a print head defines one or more rows of orifices which receive an electrically conductive recording fluid, such as for instance a water base ink, from a pressurized fluid supply manifold and eject the fluid in rows of parallel streams. Printers using such print heads accomplish graphic reproduction by selectively charging and deflecting the drops in each of the streams and depositing at least some of the drops on a print receiving medium, while others of the drops strike a drop catcher device.
In the prior art, it is known to have separate assemblies for each component of the ink jet printer. For example, there are separate assemblies for the orifice plate and the charge plate, and the components of each assembly. When an assembly needs to be replaced or repaired, there are several assemblies that need to be attended to. For instance, if a component of one assembly is replaced, the replacement component is required to be realigned with the various other components in the assembly. This, in turn, requires certain tools to be available to attempt the realignment. The process, therefore, is time consuming and costly, besides that realignment is extremely difficult to achieve.
In an effort to integrate the various components and assemblies, it is known in the prior art to contain several of the separate assemblies in a single housing. When a component had a problem, the entire assembly was removed from the housing. Unfortunately, this requires opening a housing, usually by removing various screw and attachment means, disconnecting electrical connectors between the separate assemblies within the housing, removing the problematic assembly, installing the replacement assembly, and putting the housing back together with the screw and attachment means. Obviously, the process has the disadvantage of being extremely time-consuming.
It is seen then that there is a need for a print head assembly which can be quickly and easily replaced, even in the field, and which is completely self-contained.